Are Heroes common in FLOSS projects?

Several projects rely on one or more Heroes who are the only ones who understand and know certain critical parts of a system. Often Heroes are very useful in the economy of a project but, their presence can increase the risk of project failure if they decide to leave the project. For this reason, tools for measuring the amount of spread of knowledge within a team (i.e. the Truck factor) and identifying possible Heroes are welcomed. In this paper, we have implemented a tool to compute the Truck factor and identify Heroes in a project. To assess the applicability and usefulness of the tool we have applied it to 20 randomly selected FLOSS projects. Preliminary results are encouraging: the approach seems to be applicable and useful. We found that Heroes are common in the considered set of FLOSS projects and that the Truck factor is in general low. © 2010 ACM.